Specifically, the critical % of people needed to be effectively vaccinated is 1 - (1/R0), where R0 is the "Basic Reproductive Number" of the disease. In English

Specifically, the critical % of people needed to be effectively vaccinated is 1 - (1/R0), where R0 is the "Basic Reproductive Number" of the disease. In English, how many people a single infective individual can be expected to infect in an entirely susceptible population.